In combination an archery bow and vibration dampener

ABSTRACT

A vibration dampener for an archery bow having a bow handle and a bow string. The dampener has two legs arranged in a U shape and positioned rearwardly of the belly of the bow on either side of a plane passing through and including the full length of the archery bow and the bow string. A third leg extends outwardly from the back side of the bow, and each one of said legs has a weighted member attached to its free terminal end.

United States Patent 91 Morita et al.

[ IN COMBINATION AN ARCHERY BOW AND VIBRATION DAMPENER [76] Inventors: Houyu Morita, No. 9 c/o Tanaka Bldg. 2-14 Dogenzaka 4-chome, Dhinuys-ku, Tokyo; Kazuyoshi Okino, 3050-2 Mukainada-Ohhara, Hiroshima, both of Japan [22] Filed: Apr. 9, 1971 [21] App]. No.: 132,739

[30] Foreign Application Priority Data Apr. 18, 1970 Japan 45/33762 521 U.S. Cl. 124/24, 124/30 R [51] Int. Cl. F4lb 5/00 [58] Field of Search 124/30 R, 23, 24, 124/22, 21

[56] References Cited UNITED STATES PATENTS 3,070,083 12/1962 Gobash ..124/23 Aug. 14, 1973 3,088,212 5/1963 Smith 124/23 X 3,412,725 11/1968 Hoyt 124/24 3,524,441 8/1970 Jeffery 124/30 R X Primary Examiner-Richard C. Pinkham Assistant Examiner-William R. Browne Attorney-Wenderoth, Lind & Ponack [5 7] ABSTRACT A vibration dampener for an archery bow having a bow handle and a bow string. The dampener has two legs arranged in a U shape and positioned rearwardly of the belly of the bow on either side of a plane passing through and including the full length of the archery bow and the bow string. A third leg extends outwardly from the back side of the bow, and each one of said legs has a weighted member attached to its free terminal end.

2 Claims, 5 Drawing Figures IN COMBINATION AN ARCHERY BOW AND VIBRATION DAMPENER BACKGROUND OF THE INVENTION When shooting a bow and at the instant of release of an arrow, some translational and rotational movements which occur around the gripping point of an archery bow, referred to hereinafter as the center of the reaction pressure, decrease the range and accuracy of the arrow. Stabilizers for archery bows have been proposed for effectively reducing these defective movements occuring during shooting conditions. These defective movements occuring around the gripping point of the bow are resolvable into three different movements, pitching, rolling and torque. These three movements can be considered with respect to three different planes. Plane X, which contains the longitudinal center line of the bow through the mark; plane Y, which crosses at right angles with plane X through the center of the reaction pressure and plane Z, which crosses at right angles with both plane X and Y through the center of the reaction pressure.

Prior art stabilizers for archery bows having weighting elements at the lower part of the bow handle have a considerable effect on reducing the rotational movement occuring around the center of the reaction pressure, but these weights render the bows objectionably heavy and unpractical. It has also been proposed to provide bows with one or more cylindrical stabilizers including weighting elements at the top. These are disposed outwardly at either the lower part or the upper and lower parts of the bow handle section. This arrangement reduces the undesirable movements of the archery bows under shooting conditions without objectionally increasing the total bow weight.

By spacing the weighting elements far from the center of the reaction pressure of the archery bows, they will effectively damp out the translational and rotational movements occurring around the center of the reaction pressure by increasing the mass moments of the inertia around the center of reaction pressure. In order to stabilize the bow, the weighting elements should be spaced far from the center of gravity of the bow, but this makes it difficult for an archer to shoot because of the additional heavy weight on his shoulder. This method can reduce the pitching of the bow on the plane X, but cannot effectively reduce the torque on the plain Z. Further, since the center of gravity of the bow is nearer to the back side than to the gripping point, this increases the rolling of the bow on the plane Y. To avoid these unbalanced conditions, cylindrical stabilizers are attached to the belly side of the bow handle section which make the archery bow stand perpendicular. As a result, the center of gravity will be moved to the same place as the center of the reaction pressure. In addition, the center of gravity can be removed from the center of the bows while the before said center of gravity is detached from the center of reaction pressure by attaching one or more cylindrical stabilizers to the back side of the archery bow. The length of the cylindrical stabilizer at the belly side of the bow handle section must be limited so as to be removed from the path of movement of the bow string. This also limits the length of the stabilizers at the back side of the bow handle section such that they are not sufficient to substantially increase the mass moment of inertia for resisting rotation of the bow about the plane 2.

SUMMARY OF THE INVENTION The primary object of this invention is to provide an archery bow having a bow handle section including one or more cylindrical stabilizers with weighting elements are spaced far enough from the center of gravity of the bow to bring the center of gravity to the center of the reaction pressure.

A further object is to provide a balanced weighting bow having one or more cylindrical stabilizers including weighting elements at the back side of the bow handle section and one or more bifurcated cylindrical stabilizers including weighting elements at the belly side of the bow handle section.

A comparison of the improved bow with the prior art shows that the invention has succeeded in reducing the rotational movements of the bow around the center of the reaction pressure by making the center of the reaction pressure the same as the center of the bow gravity. The cylindrical stabilizers including the weighting elements positioned far from the center of bow gravity in the manner taught in the invention, so as to considerably increase the mass moments of inertia around the center of gravity, also reduce the rotational movements of the bow about the planes X, Y andZ, which result from torsional forces being applied to the bow under the shooting conditions.

BRIEF DESCRIPTION OF DRAWING FIG. 1 is a side view of a preferred embodiment in accordance with the present invention.

FIG. 2 is a front view of the embodiment shown in FIG. 1.

FIG. 3 is sectional plan view taken along line A-A of a portion of the embodiment shown in FIG. 1.

FIG. 4 is a partial sectional plan view of a bow in accordance with a second embodiment.

FIG. 5 is a partial sectional plan view of a bow in accordance with a third embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The handle section 1 has a belly face 12 facing the bow string 3 and an opposite back face 4 and sight window 2. A cylindrical stabilizer consisting of leg 7 is attached to the back face of the bow 4 by threaded bushing 8 and a weighting element 5 is fixed at the end thereof by a stopper 6. Bushing 14 which carries a bifurcate U-shaped post 13-1, 13-2 is attached to the belly face of the bow 12. At the free ends of the legs 13-1 and 13-2 are threaded weighting elements 10-1 and 10-2 which are positioned on opposite sides of the bow string 3 and which are secured by stoppers 11-1 and 11-2. The basic pattern of this invention is an archery bow having one cylindrical stabilizer 7 projected from the lower part of the back face of the bow 4 and a bifurcate post 13-1, 13-2 including weighting elements 10-1 and 10-2 as described above. In addition, more cylindrical stabilizers could be placed at the upper back face portion 4' and at the upper belly face portion 12.

Referring to FIG. 4, instead of the bifurcate stabilizer 13-1, 13-2 two posts 17-1 and 17-2 including the weighting elements 15-1 and 15-2 fixed by the stoppers 16-1 and 16-2 can be attached to the belly face of the bow on opposite sides of the bow string 3. FIG. 5 shows a third method of placing theposts 20-1 and 20-2, in-

3 cluding the weighting elements 18-1 and 18-2 fixed by the stoppers 19-1 and 19-2. The posts 20-1 and 20-2 project from the both side of the bow handle section and have weighting elements spaced on either side of bow string 3.

Referring to FIGS. 1 to 3, weighting elements 5, -1 and 10-2 may be balanced so as to position the center of gravity at the center of the reaction pressure. These weighting elements will appreciably reduce any rotational or translational movements occurring around the point 0 on the plane Y. The mass moment of inertia with respect to the plane X is increased by spacing the said two bifurcate weighting elements on either side of the bow string as far as possible from the belly face of the bow handle section. This will reduce any rotational and translational movements occurring around the center of the reaction pressure on the plane X.

In addition, the balance of the three weighting elements will serve for increasing the mass moment of inertia with respect to the plane Z; thus, reducing any rotational and translational movements occurring around the point 0 on the plane Z. For these reasons remarkable results can be obtained in the reduction of the rotational or translational movements occurring under shooting conditions or at the instant of release.

While cylindrical stabilizers including at least three or more weighting elements reduce considerably the rotational or translational movements occurring around the center of the reaction pressure 0, the bifurcate cylindrical stabilizer spaced on either side of the bow string increases the mass moment of inertia without limiting the lengths of the stabilizers. All of these arrangments result in a bow which is light and yet easy to shoot and increase the accuracy of the bow. This invention is intended to embody any other bow constructed in accordance with the foregoing advantages. By attaching several universal joints to the cylindrical stabilizers for varying the level angle of the stabilizers, the mass moment of inertia will be able to be changed optionally under various shooting conditions.

In short, by placing the bifurcate cylindrical stabilizer at the belly face of the bow handle section, the two weighting elements, spaced on either sides of the bow string, will remove the unbalance condition of the bow resulting from one or more cylindrical stabilizers attached to the back face of the bow handle section.

What is claim is:

1. In combination, an archery bow having a bow handie, a bow string, and a vibration dampener, said vibration dampener comprising two legs arranged generally in a U-shape and positioned rearwardly of the belly of the bow, said legs being removably attachable to said handle at the central point of the U of the dampener, said dampener being bisected by a plane passing through and including the full length of the archery bow and the bow-string, said legs extending from the belly of the bow in the direction of the bowstring, each one of said legs being positioned, respectively, on opposite sides of said plane, and each leg having a weighted member attached to its free terminal end portion.

2. The combination as claimed in claim 1 wherein said vibration dampener further includes a third leg, said third leg lying substantially in said plane and extending forwardly from the back side of the bow.

t t k 

1. In combination, an archery bow having a bow handle, a bow string, and a vibration dampener, said vibration dampener comprising two legs arranged generally in a U-shape and positioned rearwardly of the belly of the bow, said legs being removably attachable to said handle at the central point of the U of the dampener, said dampener being bisected by a plane passing through and including the full length of the archery bow and the bow-string, said legs extending from the belly of the bow in the direction of the bowstring, each one of said legs being positioned, respectively, on opposite sides of said plane, and each leg having a weighted member attached to its free terminal end portion.
 2. The combination as claimed in claim 1 wherein said vibration dampener further includes a third leg, said third leg lying substantially in said plane and extending forwardly from the back side of the bow. 